JCPenney - The retailer said it expects to post revenue of $2.64 billion against current expectations for $2.74 billion, partially blaming losses on the strategies of former CEO Ron Johnson. In addition, the company said it sees same-store sales falling about 16.6 percent in the first quarter. The full results will be released in mid-May. Still, shares were higher in extended-hours trading.

Herbalife - Billionaire investor Carl Icahn discloses a 16.5 percent stake in the nutrition and weight-loss products company in a 13D/A filing, up from 15.9 percent as of March 7. Shares advanced in extended-hours trading.

Symantec - The computer security software company posted a profit of 44 cents a share, excluding one-time items, on sales of $1.75 billion, exceeding Wall Street projections for 38 cents a share on revenue of $1.73 billion. In addition, the company declared a quarterly dividend of 15 cents a share. But the company handed in a disappointing current-quarter profit guidance, sending shares lower in extended-hours trading.

WholeFoods - The upscale grocery store chain posted earnings of 76 cents a share, beating expectations by 3 cents a share, on revenue of $3.03 billion, which matched estimates. The company also raised its 2013 earnings guidance to the higher end of the expected range and reiterated its projections for sales growth of 10 to 11 percent. In addition, the board approved a 2-for-1 stock split. Shares soared in extended-hours trading.

Trip Advisor - The travel website posted earnings of 50 cents a share, excluding one-time items, on sales of $230 million, beating expectations for 46 cents a share on sales of $224 million. It also acquired vacation rentals website Niumba.com; financial terms of the deal were not disclosed. Still, shares were lower in extended-hours trading.

Mondelez - The food and beverage company posted earnings of 34 cents a share on sales of $8.7 billion, edging past expectations for 33 cents a share on sales of $8.68 billion. Shares ticked higher in extended-hours trading.

Marathon Oil - The oil and natural gas exploration and production company posted earnings of 51 cents a share,ex-items, on revenue of $4.11 billion, falling short of expectations for 72 cents a share on sales of $4.25 billion. Shares declined in extended-hours trading.

Iamgold - The gold producer posted earnings of 15 cents a share, excluding one-time items, edging past expectations by a penny a share, but revenue was much lighter than estimates at $305 million, versus forecasts for $381 million. Shares fell in extended-hours trading.

WebMD - The health information website posted a loss of 3 cents a share on sales of $113 million, topping expectations for a loss of 15 cents a share on revenue of $107 million. Shares rose in extended-hours trading.

Zillow - The online real estate database posted a loss of 11 cents a share on revenue of $39 million against forecasts for a loss of 3 cent a share on sales of $37 million. It also raised its full-year revenue outlook. Shares rallied in extended-hours trading.

DaVita - The kidney care company reported a profit of $1.84 a share on sales of $2.83 billion, beating expectations for $1.79 a share on revenue of $2.78 billion. Meanwhile, the company added that Berkshire Hathaway, which already owns about 15 percent of the dialysis company, won't take a position of more than 25 percent in the firm. Shares climbed in extended-hours trading.